Arduino voice changer turns you into [Vader]

Halloween is just around the corner, so of course we’re looking forward to a bunch of awesome costumes put together by Hackaday readers. In an effort to match his voice to his costume, [Phil Burgess] over at Adafruit (and former Hackaday alumnus) put together an Arduino-powered voice changer to give his voice the gravitas of [James Earl Jones] or the lightheartedness of a member of the Lollipop Guild.

If you’ve ever played with a turntable, you’ll know playing a 33 RPM record at 45 or 78 RPM turns your treasured copy of Dark Side of the Moon into a lighthearted aural experience with a pitch that is much too high. Likewise, playing a single at 33 or 16 RPM means those once dulcet tones are now recordings of tormented souls in an acoustic hell.

[Phil]’s voice changer operates on the same principle by recording sounds from a microphone into a circular array and playing them back at a different rate; faster if the desired effect is a Munchkin, and slower if this year’s Halloween costume will be a Sith lord.

The completed build incorporates a 10k pot to dynamically change the timbre of the voice changer, as well as an Adafruit Wave Shield to play back a few pre-recorded sounds of lightsabers clashing. In all, a very cool project for your Halloween costume that’s also a very good introduction to DSP and real-time audio modifications with a microcontroller.

This is pretty neat, however there are single chips which do this (or at least used to be)..
I think they are pretty much extinct now unless you search the charity shops for a voice changing toy with corroded batteries and perform brain surgery to extract the chip.

The simplest circuit I’ve seen for this vioce effect uses a 555 and an opto-isolator to chop the voice and give the robotic effect.
The effect is variable by using a pot in the r/c circuit that regulates the 555 astable frequency.

Lost me at the wave shield. Why not put that in the title? Arduino + Waveshield +amplified microphone=scary voice changer. Also “Halloween City” or whatever local gypsy halloween store you have in your area have voice changers for $5.00 that might fit the more budget minded tweaker. There is a resistor (R4) iirc that can be fiddled with. A 555 one like Jeff mentioned can add interesting Dahlek modulation with a robot voice changer :) EXTERMINATE your supply of candy into my bag :D